Manufacture of triarylcarbinols



Patented Aug. 23, 1932 UNITED STATESPATENT Q FFicE-If:

SAMUEL oor'rnY, or BLAcKnnY, mnnonnsrnn, ENGLAND, ASSIGNOR TO IMPE R IAL CHEMICAL INDUSTRIES LIMITED, on wnsr vnnsrnmnnenmn 'MANuFAc'runE or rnrnnrnonnnmons A ree (Amer. Chem. J. 1903, 29, 588 609), has shown that benzophenone and similar diaryl ketones react with sodium andaro- .matic bromo -compounds in the presence of dry ether to give triarylcarbinolsandv other -products. More recent research (cf. Schlenk,

Ber; 1914, 47,- 487) has indicated that the course of the reaction is not that imagined by Acree but is more probably as follows:

ONa

+NaoH The yields obtained by v Acrees method are, however, poor, especially when the attempt 1s .made to extend the reaction to other diaryl .ketones, and in particular to the use of aromaticchloro compounds.

' In Ser. Nos. 155098 and 315100 cases are described in which, under special conditions,

.tetraalkyldiaminobenzophenones are caused Y to react with aromatic halogeno compounds to yield the carbinol form of various triarylmethane dyestufis' I have now found that under conditions somewhat similar to those employed in the above mentioned specifications, but which are completely different fromthose employed by 'Acree, there can be obtained from diarylketones of the general formula in good yield.

According to our invention a mixture of the ketone and the halogeno-compound is added to the alkali metal in hot benzene or other suitable diluent at such a rate as to keep the reaction, once started, proceeding vigorcontinue heatingfor some time before work- In my process, it is advantageous to'first form a liquid mixture comprising the ketone and the halogeno-compound and a sufficient amount of an inertsolvent to give said liquid mixture, and. then'graduallyadd this first {liquid mixture to a second liquid mixture comprising an alkali metal and an inert: liquid: As' stated above this second liquid :mixture is heated orwarmedy After the first portion is added the reaction, is started, and

further gradual addition of the first liquid mixture carriesforward the reaction; the reaction mixture boiling steadily. The evaporated liquid is refluxed, that is condensed and returned to the liquidreactionmixture. In

:this way, the reaction is effected in a controlled and advantageous manner.

Any diarylketone of the general formula I .in which to and w represent hydrogen or a'n alkoxy group, may be employed according to .my invention. As examples ofsuchbodies I .mention benz'ophenone, ditolylketones, di- 1,

anisylketone (Schnackenberg and .Scholl, Ber 36 (1903) p. 654; Journal of Chemical Society Abstracts 1903, page 341) and phenyla-naphthyl ketone.

The halogen compounds may be any halogenated aromatic hydrocarbon derivative which does 'not contain other reactive groups such as nitro groups, primary amino groups, carboxylic groups, sulphonicjgroups and phenolic groups. I

The alkali metal may be sodium, potassium, lithium etc. or alloys of these. 1 p

, My invention is illustrated but not'limited by the following examples, in which the parts are byweight.

No Drawing; Application filed December 26, 1929, Serial 110415345, and in Great BritainJa nuary 1, 1929. p

ously. Usually, when all the metal has dis appeared, the reaction product is poured into water I and the diluent is removed. bysteam distillation, but occasionally it'is desirable to ago ii] I ,7 7' 7 ,2

Example 1. Diphm Z-p tolylaarbinol from benzophenone and p-chlorotoluene a6 parts of granulated sodium are placed 75 in a reflux apparatus fitted with an agitator along with a convenient amount ofbenzene,

(e. g. 15()parts). The mixture is rapidly StII'I'Gd'fiJHl the benzene warmed to its boiling point. A mixture of benzophenone,'182 parts,

tu're liquid at ordinary temperatures (on warm days the addition of benzene is unnec essary). A small quantity of this mixture,

..d i um,and benzene, which is kept. warmuntil formation'of a blue colour inthe liquid. The source of heat is thenremoved and the ketone-chlorotoluene mixture. is added at such added.thereaction vessel is kept"warm a short time to complete 7 they reaction, after "which. the contents are cooled and drowned n wat lTh e lsolvent removed by distillationin dp -t o l ylclce tmhend bromobenzene i i 46 partsof-granulatedfsodiumare stirred "with-"100 parts hot benzene and a mixture of 4 di-p-tolyl ketone (210; parts) and' bromoben- 'zene (160 parts) in suflicient warm benzene to form a solution (about 300 parts) is added at such a rate as to keep the benzene soluand the mixture kept at the boil for half an hou-r {after the addition is-finished. "The regaction' product is c then cooled, drowned in wvater, 'thesolvent removed by steamdistil- 'l ation-and the crude viscous carbinol purir fied "by recrystallization from light petroleum; or; other suitable solvent.- "It then} has a:.melting-'point' 76 77C.

5 e mama 2 L "when after aperiod'of about -minutes an 7 intense blue-colour develops, the gradual ad- Edition of}, the-"main; bulk of liquid; is begun. 'The boiling temperature is maintained with- 5 out external heating by regulating the-flow.

.and -chlorotoluene .128 parts is then made and sufiicient benzeneadded to keep themix-v say 20parts, isthen 'ad ded tot-he warm-'so-' am t a the benzene boils steadily. When all the jkG-liOIlQ-ChlOI'OtQlllGDB mixturehas been:

of liquid, until the reaction is complete. The

mass is then extracted with water, and steam distilled. The crude carbinol crystallizes on 1 cooling. 7 7

Example 4. Triphenyl ,aarbaol 5 partsof potas si'um meta' -l are melted under-300 parts of benzene, and while stirring and boiling a solution,.of 182 parts of 'beii'zophenone andj113; parts 'chlorobenzene. in 200 parts of benzene is slowly added. The

reaction at ;once, with development of a blue colour, and external heating is .unnecessary throughoutzstheaddition: ;-:{Ehe

carbinol is isolated as in'the previous examthe reactioncommences,-as isevidenced bythe 2 Emma tm h ymp w i WWW d6 parts of granulated sodium are'sus- *penjdedi1 1-200parts' of pure ether, andwhile -.-'stirringi,alsolution of143 parts o ;p-chlo-' -roaniso1e, 182 parts 'benzophenone, and-300 parts of -ether is allowedtofiow inj slowly.

The reaction begins at onceat theboiling point of ether, and continues throughout:

without external heating." :ThQgSOIutiOn is finally extractedwith water, and volatile matter is then, driven off with steam; the viscous carbinol remaining may be crystal lized from 'ether, ligroin'mixture orconverted 'benz'ene 232parts phenylz naphthyl'ketone, andrj300 parts of benzene is jallowed-itogfiow very slowly into'a vessel in which '6 parts 'of granulated sodium are stirred with 200 parts of boilingbenz'ene; When thead'di "tion is complete, the mass ;is' stirred and heatedQ i hours-longer and then treated with :water. 'Volatile'matteris' driven'ofi a tion boiling. Towards'the end of the addi- I tion heat is applied-to the reaction vessel current of steam and'the carbinolgsolidifies. E mample '7. 4.'4"- dimethQy 1'ipZzen Z10m :binvl '1 1 To parts of granulated sodiumin 200 parts of boiling'benzene, 5% lot a'solution "composed of 1431 parts pchloroanisole, 224

parts 4-m'ethoxy benzophenone, and 300 parts of benzene is 'a d'ded. After boilingifor "30 minutes a deep blue colour develops and fades again, and a vigorous evolution of heat occurs. The rest ofthe solution is then run;

inslowly, at such a rate thatthe boiling tem- In the above exa may used in place of-sodium or potassium metal, orthere may alsobe used alloysof any two or of all three of these metals;

Having now particularly; described and" .ascertained the nature of my said invention .and in what manner'the same'is to be performed, I declare that what I claim is 1. In the manufacture of triaryl carbinol compounds of the type represented by the following formula:

XRz OH wherein X represents hydrogen, an alkyl or alkoxy group, R represents a benzene or naphthalene nucleus and R and R represent benzene nuclei, and in which when R is a naphthalene nucleus, the X attached cance as above, and a halogenated compound having the formula 2.

wherein Y represents chlorine or bromine and in which X and R have the same significance as above, the process which comprises preparing first a liquid mixture of an inert organic liquid and an alkali metal by heating together said liquid and said metal,

preparing a second liquid mixture comprising an inert organic liquld, said benzophenone compound and said halogenated aryl compound, gradually adding the second liquid mixture to the first liquid mixture at such a rate that the reaction mixture is maintained at boiling temperature, thus effecting pound in the presence of a boiling liquid mixture comprising an inert liquid and an alkali metal, in a controlled manner to form said triaryl carbinol.

2. The process of claim 1 in which the benzophenone compound is a body having the probable formula R1\ o o wherein R and R represent a benzene nucleus.

3. The process of claim 1 in which the halogenated aryl compound is a body having the V probable formula Y m R3 R4,

wherein R represents a benzene nucleus, Y V

.wherein Y representschlorine or andX represents hydrogen, an alkyl or alk-' I oxy group, the said reaction being effected v in the presence of a boiling liquid mixture zophenone compound'is a body-having the probable formula:

l Rec-#111 o=o I I I, V, R roj-Rz r wherein R and R represent a benzene nucleus, and R represents an alkyl group.

5. The process of claim 1 in which the halogenated aryl compound is abody having the probable formula wherein R represents a benzene nucleus, Y represents chlorine or bromine, and R represents an alkyl group.

6. The process of claim 1 in which the halogenated arylicompound is a body havingthe probable formula thereto represents hydrogen, from a benzophenone compound having the probable forwhereinR represents a benzene nucleus and X represents hydrogen, an aklyl or alkoxy group. i i

7. The process of claim 1 in which the inert liquid is ether.

8. The process of claim 1 in which the alkali metal is sodium.

- :9. The process of claim 1 in which the alkali metal is. an alloy comprising two or more alkali metals. 7

10. In the manufacture of triaryl carbinols,

the process which comprises reacting together "a benzophenone compound having the prob able formula wherein X represents'hydrogen, an alkyl or alkoxy group, and'a halogenated aryl compound having the probable formula reactlon between the said benzophenone compound and the said halogenated aryl combromine,

comprising an inert liquid and an alkali metal.

.11. In the manufacture of triaryl carbinols,

probable formula jthe process which comprises reacting together i a benzophenonecompound having the probable fomula 1 k I and a halogenated arylcompound having the the said reaction being effected in the presence L o F probableformula 1 55 having the formula:

of a-gboilingliquid mixture comprising; ether and sodium. i y s. 1; --J

12. In the manufacture of triaryl carbinols,

the processrwhichcomprises,reacting together able formula a benzophenone compound haying the prob- H3CO+- i I and a halo enated ,arylcompound having the i-anditmmsaidtriaryl carbinol; the said secand; liquid mixture being/ate atemperature suificient toiefiect:aninitial reactionand the reaction being controlled by gradually: adding 1 the first; liquid: mixture to the second liquid mixture eat-such; a'rateas to maintain the reaction mi ats vT l ne o n ndy Q0 i'd sing and tu n t b i d ifi inert liquid torthereaction mixtureri In testimony whereof Laflix my signature.

SAMUEL COFFEY.

'thesaid reaction being efiectedin the pres- 1 "'ence' of a boiling liquid mixture comprising benzene and sodium. 7

13. In the manufacture oftriaryl carbinols, the process which comprises reacting toether a benzophenone compound having-the probable formula l and a halogenatedarylc mpoundwhaving the the reaction 1 effected the f 'presence of a boiling'liquid mixturecomprising" Y 35 benzene and sodium.

sent benzene nuclei,a'nd in whichwhen R is e a 'naphthal'ene'n-ucleus, the Xattachedzthereto represents hydrogen, fromabenzophen'one {compound having the probable formula; i VV E E NLM .7 v r 7 0:0 ..XR2/ I V h e X5111 an B5 h ve: he a e s ni wc n as. bove, a d 1 gen ted.- 0mp u d wherein Y represents chlorine or bromine and in which X and Rgjhavel the same'signifi- L160, canceas above, the process which comprises "gradually adding aliquid mixture comp'rismg said benzophenone compound; said halogenated aryl compoun'd and-an inert liquid r to a second liquid mixture comprising an inert rliquid-andan alkali metal; to; effect reaction 

